{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43408", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.008Z", "datePublished": "2026-05-08T14:21:47.579Z", "dateUpdated": "2026-08-05T12:27:51.489Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:27:51.489Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: add a bunch of missing ceph_path_info initializers\n\nceph_mdsc_build_path() must be called with a zero-initialized\nceph_path_info parameter, or else the following\nceph_mdsc_free_path_info() may crash.\n\nExample crash (on Linux 6.18.12):\n\n virt_to_cache: Object is not a Slab page!\n WARNING: CPU: 184 PID: 2871736 at mm/slub.c:6732 kmem_cache_free+0x316/0x400\n [...]\n Call Trace:\n [...]\n ceph_open+0x13d/0x3e0\n do_dentry_open+0x134/0x480\n vfs_open+0x2a/0xe0\n path_openat+0x9a3/0x1160\n [...]\n cache_from_obj: Wrong slab cache. names_cache but object is from ceph_inode_info\n WARNING: CPU: 184 PID: 2871736 at mm/slub.c:6746 kmem_cache_free+0x2dd/0x400\n [...]\n kernel BUG at mm/slub.c:634!\n Oops: invalid opcode: 0000 [#1] SMP NOPTI\n RIP: 0010:__slab_free+0x1a4/0x350\n\nSome of the ceph_mdsc_build_path() callers had initializers, but\nothers had not, even though they were all added by commit 15f519e9f883\n(\"ceph: fix race condition validating r_parent before applying state\").\nThe ones without initializer are suspectible to random crashes. (I can\nimagine it could even be possible to exploit this bug to elevate\nprivileges.)\n\nUnfortunately, these Ceph functions are undocumented and its semantics\ncan only be derived from the code. I see that ceph_mdsc_build_path()\ninitializes the structure only on success, but not on error.\n\nCalling ceph_mdsc_free_path_info() after a failed\nceph_mdsc_build_path() call does not even make sense, but that's what\nall callers do, and for it to be safe, the structure must be\nzero-initialized. The least intrusive approach to fix this is\ntherefore to add initializers everywhere." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - Reachable through local VFS operations on an already-mounted Ceph filesystem, such as open/create, unlink/rmdir, and setattr/truncate/chmod paths. It is not directly reachable from unauthenticated network packets.\nAC:L - An unprivileged user can create or access Ceph paths that make ceph_mdsc_build_path() fail, such as over-PATH_MAX dentry paths, and the faulty free path runs immediately afterward. No race or external timing condition is required.\nPR:L - The attacker needs only ordinary local user access to a Ceph mount with filesystem permissions to operate on relevant files or directories. No real root or kernel capability is required once the filesystem is mounted.\nUI:N - The attacker triggers the vulnerable path directly with their own filesystem syscalls. No separate victim action is required.\nS:U - The corruption occurs inside the local kernel Ceph client and impacts the same kernel security authority. It does not cross a VM, IOMMU, or other separate security scope boundary.\nC:H - The missing initializer can make ceph_mdsc_free_path_info() kfree a stale or attacker-influenced kernel heap pointer, creating heap corruption. Under the required high-severity tie break, this is treated as capable of yielding kernel memory disclosure primitives.\nI:H - The invalid or double free of a path buffer is kernel heap memory corruption and can plausibly be shaped into write/control-flow corruption. Under the required high-severity tie break, integrity impact is High.\nA:H - The fix commit includes real crashes with invalid slab frees and a kernel BUG/Oops in the Ceph open path. A local attacker can repeatedly trigger a kernel crash, causing high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ceph/debugfs.c", "fs/ceph/dir.c", "fs/ceph/file.c", "fs/ceph/inode.c" ], "versions": [ { "version": "db378e6f83ec705c6091c65d482d555edc2b0a72", "lessThan": "644b47f0574fd82aeb9d00317eca8d1f2a525c8c", "status": "affected", "versionType": "git" }, { "version": "15f519e9f883b316d86e2bb6b767a023aafd9d83", "lessThan": "8be8911f590813e6f90bc6407ced1b23e50bc5da", "status": "affected", "versionType": "git" }, { "version": "15f519e9f883b316d86e2bb6b767a023aafd9d83", "lessThan": "453df1f4535842bf17ff1885a225e153d7ee3374", "status": "affected", "versionType": "git" }, { "version": "15f519e9f883b316d86e2bb6b767a023aafd9d83", "lessThan": "43323a5934b660afae687e8e4e95ac328615a5c4", "status": "affected", "versionType": "git" }, { "version": "2bfe45987eb346e299d9f763f9cd05f77011519f", "status": "affected", "versionType": "git" }, { "version": "6.12.48", "lessThan": "6.12.78", "status": "affected", "versionType": "semver" }, { "version": "6.16.8", "lessThan": "6.17", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ceph/debugfs.c", "fs/ceph/dir.c", "fs/ceph/file.c", "fs/ceph/inode.c" ], "versions": [ { "version": "6.17", "status": "affected" }, { "version": "0", "lessThan": "6.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.19", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.9", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.48", "versionEndExcluding": "6.12.78" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "6.18.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "6.19.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.0" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16.8" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/644b47f0574fd82aeb9d00317eca8d1f2a525c8c" }, { "url": "https://git.kernel.org/stable/c/8be8911f590813e6f90bc6407ced1b23e50bc5da" }, { "url": "https://git.kernel.org/stable/c/453df1f4535842bf17ff1885a225e153d7ee3374" }, { "url": "https://git.kernel.org/stable/c/43323a5934b660afae687e8e4e95ac328615a5c4" } ], "title": "ceph: add a bunch of missing ceph_path_info initializers", "x_generator": { "engine": "bippy-1.2.0" } } } }